Footswitches are used with a variety of electrical and mechanical equipment and, in particular, have become an accepted part of the operator controls that enable the use of microsurgical and ophthalmic systems. Accordingly, the present footswitch invention will be described in terms of its use with microsurgical systems and, in particular, its use with ophthalmic laser surgical systems.
When surgically treating a patient, for example, during ophthalmic surgery, a surgeon may use a complex patient treatment apparatus/surgical system that may require the control of a variety of different pneumatic and electronically driven subsystems: Typically, the operation of these subsystems is controlled by a microprocessor-driven console. The microprocessor within the surgical console may receive mechanical inputs from either the surgeon/operator or from an assistant to the surgeon/operator. For example, an assistant may directly manipulate controls on the surgical console, while the surgeon/operator may use a control input device, such as a footswitch, to provide mechanical inputs. In the case of a footswitch, the mechanical inputs originate from the movement of the surgeon's foot to control the operation of a subsystem within the surgical system. The mechanical inputs are translated into electrical signals that are then fed to the microprocessor to control the operational characteristics of the desired subsystem. One example of such a subsystem is a laser system used in ophthalmic laser eye surgery, such as the EYELITE® photocoagulator manufactured by Alcon Laboratories, Inc. of Irvine, Calif.
Examples of footswitches designed for translating mechanical inputs into control signals for a complex patient treatment apparatus may be found in several U.S. Patents, including U.S. Pat. Nos. 4,837,857 (Scheller, et al.), 4,965,417 (Massie), 4,983,901 (Lehmer), 5,091,656 (Gahn), 5,268,624 (Zanger), 5,554,894 (Sepielli), 5,580,347 (Reimels), 5,635,777 (Telymonde, et al), 5,787,760 (Thorlakson), 5,983,749 (Holtorf), and 6,179,829 B1 (Bisch, et al), and in International Patent Application Publication Nos. WO 98/08442 (Bisch, et al.), WO 00/12037 (Chen), and WO 02/01310 (Chen). These patents and patent applications focus primarily on footswitches that include a foot pedal or tillable treadle similar to the accelerator pedal used to govern the speed of an automobile. The movement of the foot pedal or tillable treadle typically provides a linear control input. Such linear control inputs may be used, for example, for regulating vacuum, rotational speed, power, or reciprocal motion.
Certain footswitches, however, such as those used for ophthalmic laser surgery, may consist primarily of a casing having a switch operably connected to the laser surgical system. The switch is typically a single on/off type switch dedicated to firing a laser that has been previously placed in a “ready” condition. In a typical ophthalmic laser surgery, such as for photocoagulation, a laser subsystem is first prepared for the surgery by, for example, setting the proper parameters for the type of surgery, (e.g., power level, pulse duration, shot pattern, etc.) The laser is typically in a stand-by state (laser on, but incapable of being fired from the footswitch) when the laser system is powered on. For safety reasons, the user must take an affirmative step to place the laser in a “ready” condition from the stand-by state. A laser in the “ready” condition is configured to fire when the fire switch in the footswitch is actuated. Thus, there must be a conscious user decision to change the laser state from “stand-by” to “ready” by, for example, actuation of a button on the laser system console. Typically, a regulatory requirement imposes the additional restriction of a minimum two-second delay (internal to the console) between switching to the “ready” state and the laser actually entering the “ready” state.
To place a laser in a “ready” condition, typically a surgical assistant must manipulate a control at the control panel of the surgical subsystem; for example, the assistant may press a button that switches the laser from stand-by to ready. A surgical assistant typically performs this function because during a surgical procedure, at the point when the laser is needed, the surgeon is well into the surgery and not at a point where he/she may readily extricate from the surgical field to manipulate controls at the surgical console without disrupting the surgery. Further, in some instances the surgeon may be engaged in the surgical field and the assistant may also be otherwise engaged away from the control panel. A delay and inefficiency are imposed by requiring the assistant or the surgeon to move to the control panel to prepare the laser. A surgeon is thus typically dependent on a surgical assistant to perform this function for him or her.
Prior art systems do not provide a means by which a surgeon can, independently of an assistant, easily place a laser in a ready position and continue with the laser surgery without having to detract attention from the surgery. Instead, the surgeon must rely on an assistant. Once the laser is in a ready state, however, prior art systems do provide a firing switch in the laser system footswitch that the surgeon can actuate to fire the laser.
Therefore, a need exists for a multifunction surgical footswitch that can provide a surgeon the ability to independently operate a laser of an ophthalmic laser surgical system while maintaining his/her attention within a surgical field.